The best wood for a sauna

Before comparing species, it helps to know what you are actually judging them on. Four qualities do most of the work: resin content (how much a wood tends to sweat or soften under heat), scent (how strong and how pleasant the aroma is once warmed), appearance (color, grain and how many knots a given grade carries), and cost tier relative to the other options.

Structural strength and heat performance matter far less between these species than people expect — all of the woods commonly used in saunas are suitable for the job, or they would not be used at all. The differences that actually show up day to day are about comfort, smell and looks, which is exactly why this comes down to preference and budget more than a single objectively correct choice.

It is also common to mix woods within one build — using one species for the walls and ceiling, and a different, lower-resin wood specifically for the benches, where skin contact is direct and sustained.

Cedar is the wood most people picture when they think of a sauna, and it earns that reputation through a genuinely good combination of traits. It carries a distinctive, warm aroma that intensifies with heat, is naturally resistant to moisture and decay, and generally has low resin content, which keeps it comfortable against skin on the benches.

The trade-off is cost. Cedar typically sits at the higher end of the price range among common sauna woods, and that premium is real. For many builders it is worth it for the scent and durability alone, but it is not the only reasonable choice, and a lower-cost wood is not a compromise on safety or function — just on a different set of qualities.

Hemlock is a common mid-range choice, pale in color with a relatively subtle grain and a much milder scent than cedar. It is widely used in commercial and kit saunas partly because it is generally more affordable than cedar while still being well suited to the sauna environment.

Basswood and aspen are both light, pale, low-resin woods that tend to sit toward the budget-friendly end of the range. They have a much fainter scent than cedar, which some people actually prefer if they find a strong wood aroma overwhelming in a small, hot room, and both are commonly chosen for bench wood specifically because of their low resin content, even in a build that uses another wood for the walls.

Spruce shows up in some traditional and budget builds as well. It carries a more noticeable grain and, depending on grade, can have a higher resin content than the woods above, which is worth checking for if resin against skin is a concern for you, particularly on bench surfaces.

None of these are a downgrade from cedar in any absolute sense — they are simply different points on the scent, appearance and cost spectrum, and any of them can make a perfectly good sauna when installed properly.

Within any given wood species, the grade matters as much as the species itself. Sauna lumber is typically sold in different grades based on how many knots it has and how tight and sound those knots are. A clear or lightly knotted grade looks cleaner and can have a marginal edge in structural consistency, while a knottier grade costs less and gives the wood more visible character, which plenty of builders actually prefer for the rustic look.

• Look for tight, sound knots rather than loose ones that could work free with repeated heat cycling.
• Kiln-dried lumber, dried specifically for the moisture range a sauna will put it through, is generally preferred over green or air-dried stock.
• Check that boards are free of any coating, stain or treatment not rated for sauna heat — anything applied to the wood needs to be food- and heat-safe given how close it sits to bare skin.

If you are ordering a pre-cut kit, the wood grade is usually specified up front and is one of the differences between budget and premium kit tiers, which our kit vs custom build guide covers in more detail.

A practical way to approach the decision is to separate it into two questions: what goes on the walls and ceiling, and what goes on the benches. The walls and ceiling are seen and smelled more than touched directly, so scent and appearance can lead the decision there. Cedar or hemlock both do this job well, largely based on budget and how strong an aroma you want.

The benches are a different question, because bare skin sits directly against that wood for the length of a session. Low resin content and a smooth, splinter-free surface matter most here, which is why basswood and aspen are popular bench choices even in builds that use a different wood elsewhere. Our sauna benches guide goes further into bench layout and wood choice specifically.

However you split it, the honest bottom line is that any of these commonly used woods, chosen in a sound grade and installed correctly, will serve you well — the decision is really about which combination of scent, look and cost fits your build and your budget.